The present application pertains to flexible walled coolers or "thermally insulating carriers" for preventing temperature change of heated or cooled items placed in such a carrier.
Portable containers for carrying heated or cooled items such as food or beverages are very popular since they provide the ability to prevent the change in temperature of heated or cooled items over a period of time. Many individuals use such thermally insulated carriers for maintaining the temperature of food and beverages when camping, attending sporting advents or other spectator activities, or any other activity in which refrigeration or heating is not easily accessible or maintainable. Further, such thermally insulating carriers have enjoyed a great deal of popularity in other noncustomary applications such as in medicine where chemicals or various samples must be maintained at a predetermined desired temperature in the absence of electrical or other energized heating or cooling systems.
More recently, softwalled carriers have gained a high degree of popularity with consumers. Softwalled carriers provide several advantages over the standard hardwalled coolers, including lighter weight, greater portability, and greater comfort when transporting such coolers. Softwalled carriers are typically constructed by sandwiching a section of thermally insulating foam between two pieces of flexible fabric. Several pieces of this sandwiched component are stitched together to achieve a desired final shape.
The problem with such softwalled carriers is that they do not provide structural support or waterproofing achieved with the hardwalled coolers. Structural support is desirable in order to provide ease of movement so that the flexible insulating container portion of the carrier does not sag when the carrier is transported. Further, support is necessary to protect the contents of the carrier from being crushed by impact or loads placed on top of the carrier.
Waterproofing is desirable for several reasons. First, when the carrier is used to maintain the temperature of cold items, ice or some other cold medium is used to maintain the cooled temperature. As the ice or other medium melts, water or some other liquid is created which tends to accumulate inside the carrier. Most softwalled carriers tend to leak, as they are sewn together, and the seams become saturated and provide a path for leakage. This leakage may also result in saturation of the thermally insulating material which hinders its ability to provide a thermal barrier.
Another problem with available softwalled carriers is that the construction techniques, such as sewing, result in corner crevices being formed between side wall portions and the base as well as vertical corners where the sidewall portions meet. These crevices accumulate particles and other debris and render cleaning difficult. This is a particular problem when the cooler is used to transport food as the accumulated particles may deteriorate and creating decay and making the carrier rancid.